scholarly journals Demonstration of Tryptophan-Like Fluorescence Sensor Concepts for Fecal Exposure Detection in Drinking Water in Remote and Resource Constrained Settings

2020 ◽  
Vol 12 (9) ◽  
pp. 3768 ◽  
Author(s):  
Emily Bedell ◽  
Taylor Sharpe ◽  
Timothy Purvis ◽  
Joe Brown ◽  
Evan Thomas
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
High Risk ◽  
Low Cost ◽  
Fecal Contamination ◽  
Close Correlation ◽  
E Coli ◽  
Novel Device ◽  
Contamination Levels ◽  
High Risk Drinking

Low-cost, field-deployable, near-time methods for assessing water quality are not available when and where waterborne infection risks are greatest. We describe the development and testing of a novel device for the measurement of tryptophan-like fluorescence (TLF), making use of recent advances in deep-ultraviolet light emitting diodes (UV-LEDs) and sensitive semiconductor photodiodes and photomultipliers. TLF is an emerging indicator of water quality that is associated with members of the coliform group of bacteria and therefore potential fecal contamination. Following the demonstration of close correlation between TLF and E. coli in model waters and proof of principle with sensitivity of 4 CFU/mL for E. coli, we further developed a two-LED flow-through configuration capable of detecting TLF levels corresponding to “high risk” fecal contamination levels (>10 CFU/100 mL). Findings to date suggest that this device represents a scalable solution for remote monitoring of drinking water supplies to identify high-risk drinking water in near-time. Such information can be immediately actionable to reduce risks.

scholarly journals The rationale for introducing the indices «Generalized coliform bacteria» and «Escherichia coli» into the scheme of sanitary and microbiological control of water quality as indices of fecal contamination

2021 ◽  
Vol 99 (12) ◽  
pp. 1353-1359
Author(s):  
Angelika V. Zagainova ◽  
Galina M. Trukhina ◽  
Yury A. Rakhmanin ◽  
Tamara Z. Artemova ◽  
Marina A. Sukhina
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Drinking Water ◽  
Fecal Contamination ◽  
Coliform Bacteria ◽  
E Coli ◽  
Intestinal Infections ◽  
Safety Of Drinking Water ◽  
Microbiological Indicators

Introduction. The increasing bacterial contamination of water bodies requires an increase in water quality control’s reliability to ensure epidemic safety against waterborne infections. Therefore, researchers in both Russia and Europe came to the conclusion that it is necessary to search for indicator microorganisms that can more accurately suggest the presence of pathogens. microorganisms in water than traditional indicators. The aim of the study was to justify the introduction of indicator indices of fecal contamination “generalized coliform bacteria” and Escherichia coli to assess the safety of drinking water Material and methods. The article provides an analysis of domestic and international regulatory documents and literary materials regulating the quality of drinking water in terms of sanitary and microbiological indicators and assessment criteria. The results of many years of experimental and field research carried out by research organizations and practical organizations of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare are presented. Results. On the territory of Russia, “general coliform bacteria,” is one of the indicator indices chosen according to the fermentation of lactose, determine the safety of drinking water. The water does not take into account pathogenic bacteria (Salmonella, Shigella) and a number of lactose-negative opportunistic bacteria, causative agents of intestinal infections. The study of microorganisms isolated from the feces of patients confirms the frequency of occurrence of lactose-negative microorganisms to varying from 20 to 100% of strains. With an annual trend towards a decrease in the percentage of non-standard drinking water samples in terms of microbiological indices, general intestinal infections (GII) of unknown etiology increase, i.e. risk of GII. If the quality of drinking water does not correspond to thermotolerant coliform bacteria (TCB), 95% of samples contain E. coli. Therefore, the determination of E. coli more reliably indicates the intake of fresh fecal contamination and provides efficiency in taking measures to eliminate an unfavorable situation than TCB. Conclusion. Reasons are given for the introduction of more reliable microbiological indicators of water safety control, such as - “generalized coliform bacteria” with the preservation of the abbreviation GCB, combining both lactose-positive and lactose-negative bacteria, determined by the sign of glucose fermentation, negative oxidase test and negative stain according to Gram and E. coli as an indicator of recent faecal contamination, which will allow the assessment of water quality for a wide range of bacteria of the order Enterobacterials, corresponding to the modern taxonomy of Enterobacteriaceae NCBI, will ensure harmonization with international requirements and the safety of drinking water for the population.

scholarly journals Escherichia coli (E. coli) as an Indicator of Fecal Contamination in Water: A Review

2019 ◽  
Author(s):  
Farhan Mohammad Khan ◽  
Rajiv Gupta
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Drinking Water ◽  
Fecal Coliform ◽  
Fecal Contamination ◽  
Waterborne Diseases ◽  
Fecal Matter ◽  
E Coli ◽  
Detection Techniques ◽  
Pollution Indicator

Escherichia coli or E. coli is a member of the fecal coliform group and is a more specific indicator of fecal contamination than other fecal coliform species, its presence indicate possibly presence of harmful bacteria which will cause diseases and it also suggests the extent as well as the nature of the contaminants. E. coli bacteria able to survive in water for 4 – 12 weeks and at present, it appears as an indicator to provide the accurate bacterial contamination of fecal matter in drinking water, because of the availability of simple, affordable, fast, sensitive and exact detection techniques. According to the laboratory experiment based techniques, 24 - 48 hours are required for the bacterial concentration to be reported. So, there is a necessity for continuous monitoring. Techniques for detection of many pathogenic bacterial strains are not yet available, sometimes days to weeks are required to get the results. To overcome the difficulties, expensive and time-consuming techniques are required to detect, count and identify the presence of specific bacterial strain. Public health relies on online monitoring of water quality that depends majorly on examination of fecal indicator bacteria, thus protection of health requires fecal pollution indicator so that it is not required to analyze drinking water to overcome the problems associated with waterborne diseases. This paper will brief the classification, sources, survival of E. coli bacteria and its correlation with basic water quality parameters in water sources.```

scholarly journals Unsealed tubewells lead to increased fecal contamination of drinking water

2012 ◽  
Vol 10 (4) ◽  
pp. 565-578 ◽  
Author(s):  
Peter S. K. Knappett ◽  
Larry D. McKay ◽  
Alice Layton ◽  
Daniel E. Williams ◽  
Md. J. Alam ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Quantitative Polymerase Chain Reaction ◽  
Fecal Contamination ◽  
Wet Season ◽  
Fecal Indicator ◽  
Monitoring Wells ◽  
E Coli ◽  
Detection Frequency ◽  
The Impact

Bangladesh is underlain by shallow aquifers in which millions of drinking water wells are emplaced without annular seals. Fecal contamination has been widely detected in private tubewells. To evaluate the impact of well construction on microbial water quality 35 private tubewells (11 with intact cement platforms, 19 without) and 17 monitoring wells (11 with the annulus sealed with cement, six unsealed) were monitored for culturable Escherichia coli over 18 months. Additionally, two ‘snapshot’ sampling events were performed on a subset of wells during late-dry and early-wet seasons, wherein the fecal indicator bacteria (FIB) E. coli, Bacteroidales and the pathogenicity genes eltA (enterotoxigenic E. coli; ETEC), ipaH (Shigella) and 40/41 hexon (adenovirus) were detected using quantitative polymerase chain reaction (qPCR). No difference in E. coli detection frequency was found between tubewells with and without platforms. Unsealed private wells, however, contained culturable E. coli more frequently and higher concentrations of FIB than sealed monitoring wells (p < 0.05), suggestive of rapid downward flow along unsealed annuli. As a group the pathogens ETEC, Shigella and adenovirus were detected more frequently (10/22) during the wet season than the dry season (2/20). This suggests proper sealing of private tubewell annuli may lead to substantial improvements in microbial drinking water quality.

scholarly journals Drinking Water Quality and the Geospatial Distribution of Notified Gastro-Intestinal Infections / Kvaliteta Pitne Vode in Geoprostorska Porazdelitev Prijavljenih Črevesnih Okužb

2015 ◽  
Vol 54 (3) ◽  
pp. 194-203
Author(s):  
Eva Grilc ◽  
Ivanka Gale ◽  
Aleš Veršič ◽  
Tina Žagar ◽  
Maja Sočan
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Hot Spots ◽  
Fecal Contamination ◽  
P Value ◽  
Gastrointestinal Infections ◽  
E Coli ◽  
Intestinal Infections ◽  
The Impact ◽  
Drinking Water Samples

Abstract Introduction. Even brief episodes of fecal contamination of drinking water can lead directly to illness in the consumers. In water-borne outbreaks, the connection between poor microbial water quality and disease can be quickly identified. The impact of non-compliant drinking water samples due to E. coli taken for regular monitoring on the incidence of notified acute gastrointestinal infections has not yet been studied. Methods. The objective of this study was to analyse the geographical distribution of notified acute gastrointestinal infections (AGI) in Slovenia in 2010, with hotspot identification. The second aim of the study was to correlate the fecal contamination of water supply system on the settlement level with the distribution of notified AGI cases. Spatial analysis using geo-information technology and other methods were used. Results. Hot spots with the highest proportion of notified AGI cases were mainly identified in areas with small supply zones. The risk for getting AGI was drinking water contaminated with E. coli from supply zones with 50-1000 users: RR was 1.25 and significantly greater than one (p-value less than 0.001). Conclusion. This study showed the correlation between the frequency of notified AGI cases and noncompliant results in drinking water monitoring.

A sensitive presence/absence test kit for detection of coliforms in drinking water

2016 ◽  
Vol 16 (5) ◽  
pp. 1320-1326 ◽  
Author(s):  
Ashish Tambi ◽  
Urmila Brighu ◽  
A. B. Gupta
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Low Cost ◽  
Research Work ◽  
Bacterial Indicator ◽  
Test Kit ◽  
Site Water ◽  
Microbiological Water Quality ◽  
Contamination Levels ◽  
Local Populace

Coliforms are the most widely accepted bacterial indicator of fecal pollution in water. Several commercially available portable kits make it possible to carry out on-site water quality testing, but are usually costly and often require technical expertise to operate. In developing countries like India, presence/absence test kits like the H2S test kits are commonly used for routine microbiological water quality examination. H2S test kits require an incubation time of more than 24 hours and often gives false positive results. In this research work, we have developed a low-cost and sensitive test kit (ColiPAT) for the detection of coliforms including Escherichia coli in drinking water. The kit can detect very low contamination levels down to 2 coliforms/100 mL within 18 hours at 35 °C. The ColiPAT kit does not lose its sensitivity in the typical indoor temperature range of 27 °C to 35 °C. ColiPAT is also affordable and easy to perform so that local populace can conduct the test independently. This paper presents the results of sensitivity and specificity analysis of a ColiPAT kit and its comparison with the H2S test kits as standardized using Colilert method.

scholarly journals Comparison of the ColiPlate™ Kit with Two Common E. coli Enumeration Methods for Water

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1804
Author(s):  
Cassi J. Gibson ◽  
Abraham K. Maritim ◽  
Jason W. Marion
Keyword(s):  
High Risk ◽  
Natural Water ◽  
Membrane Filtration ◽  
Fecal Contamination ◽  
Reference Method ◽  
World Health ◽  
Risk Levels ◽  
E Coli ◽  
Field Samples ◽  
Very High

Quantitatively assessing fecal indicator bacteria in drinking water from limited resource settings (e.g., disasters, remote areas) can inform public health strategies for reducing waterborne illnesses. This study aimed to compare two common approaches for quantifying Escherichia coli (E. coli) density in natural water versus the ColiPlate™ kit approach. For comparing methods, 41 field samples from natural water sources in Kentucky (USA) were collected. E. coli densities were then determined by (1) membrane filtration in conjunction with modified membrane-thermotolerant E. coli (mTEC) agar, (2) Idexx Quanti-Tray® 2000 with the Colilert® substrate, and (3) the Bluewater Biosciences ColiPlate kit. Significant correlations were observed between E. coli density data for all three methods (p < 0.001). Paired t-test results showed no difference in E. coli densities determined by all the methods (p > 0.05). Upon assigning modified mTEC as the reference method for determining the World Health Organization-assigned “very high-risk” levels of fecal contamination (> 100 E. coli CFU/100 mL), both ColiPlate and Colilert exhibited excellent discrimination for screening very high-risk levels according to the area under the receiver operating characteristic curve (~89%). These data suggest ColiPlate continues to be an effective monitoring tool for quantifying E. coli density and characterizing fecal contamination risks from water.

Drinking water quality and antibiotic resistance of E. coli and Salmonella spp. from different sources in Gweru urban, Zimbabwe

2021 ◽  
Vol 193 (8) ◽  
Author(s):  
Desmond Tichaona Mugadza ◽  
Sibusisiwe Isabel Nduku ◽  
Edlyn Gweme ◽  
Sherpherd Manhokwe ◽  
Patience Marume ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Antibiotic Resistance ◽  
Drinking Water Quality ◽  
Salmonella Spp ◽  
E Coli ◽  
Different Sources

Physico-chemical and Biological Properties of Groundwater Quality in Rural Settlement, Nadi, Fiji

2021 ◽  
Vol 18 (1) ◽  
pp. 1-6
Author(s):  
Roselyn Naidu ◽  
Lionel Joseph ◽  
Syed Sauban Ghani
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Biological Properties ◽  
Drinking Water Quality ◽  
World Health ◽  
Wet Season ◽  
Potential Health ◽  
Drinking Water Contamination ◽  
Contamination Levels ◽  
Health Organization

The current study investigated drinking water quality of samples taken from Arolevu village, a locality situated in Nadi, Fiji. The groundwater samples were collected and subjected to a comprehensive physicochemical and biological analysis. The analysis for the drinking water sample was conducted seasonally, six times a year, that is, three for the dry season and three for the wet season. The results retrieved from the analysis were compared to its maximum contamination levels (MCLs) based on the health-based guidelines provided by the World Health Organization (WHO). The WHO standards were used as an attribute to determine the sources of contaminants likely to be present at the study site. A degradation trend in drinking water quality in the context of climate change may lead to potential health impacts. Hence, it is important to understand seasonal variations in drinking water quality. A proper understanding of the drinking water quality through seasonal water analysis for nitrate, nitrite, potassium, calcium, magnesium and chlorine content as well as its microbiological presence to reduce preventable risks such as using calculated amounts of fertilisers and upgrading the sewerage system to alleviate drinking water contamination is devised through this study.

A novel low-cost multi-barrier system for drinking water treatment in rural and suburban areas

2019 ◽  
Vol 15 (1) ◽  
pp. 48-65 ◽  
Author(s):  
Stephen Siwila ◽  
Isobel C. Brink
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Granular Media ◽  
Low Cost ◽  
Water System ◽  
Drinking Water Treatment ◽  
Fecal Coliforms ◽  
E Coli ◽  
Suburban Areas ◽  
Novel Concept

Abstract A low-cost multi-barrier drinking water system incorporating geotextile fabric for pre-filtration, silver-coated ceramic granular media (SCCGM) for filtration and disinfection, granular activated carbon (GAC) as an adsorption media and a safe storage compartment for treated water has been developed and tested. The developed system offers a novel concept of point-of-use drinking water treatment in rural and suburban areas of developing countries. The system is primarily aimed at bacterial and aesthetic improvement and has been optimised to produce &gt;99.99% E. coli and fecal coliforms removal. Although particular emphasis was placed on the elimination of bacteria, improvement of the acceptability aspects of water was also given high priority so that users are not motivated to use more appealing but potentially unsafe sources. This paper discusses key system features and contaminant removal performance. A system using SCCGM only was also tested alongside the multi-barrier system. Strengths and weaknesses of the system are also presented. Both the developed and SCCGM-only systems consistently provided &gt;99.99% E. coli and fecal coliforms removal at an optimum flow of 2 L/h. The developed system significantly recorded improvements of aesthetic aspects (turbidity, color, taste and odor). Average turbidity removals were 99.2% and 90.2% by the multi-barrier and SCCGM-only systems respectively.

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